Email is such a important part of our daily lives and having your email do what you would like is so important. With Gmail you can customize it with Labs. I know in previous threads we have talked about this before however there are new labs out there so you might want to check it out again. So if your are not familiar with Labs you can kinda think of them as apps for your Gmail.
At the top of your Gmail click on the green hourglass or if you don't have that then click on "Settings"
From there click on the tab that says "Labs"
Now once you find a Lab that you want to try you need to click on the "Enable" and Don't Forget To Click On Save At The Bottom! Now some lavs require you to also go to your settings and set them to your liking. For example the Lab "Undo Send" has different settings.
All of the pictures in this thread were resized to fit. Click on each picture if you would like to see it in full size.